v4 preprocessor/macro: a double at-sign (@@) can be used to output a single...

v4 preprocessor/macro: a double at-sign (@@) can be used to output a single at-sign (@); useful for Matlab function handles


git-svn-id: https://www.dynare.org/svn/dynare/dynare_v4@1747 ac1d8469-bf42-47a9-8791-bf33cf982152